This nationwide analysis of commercial energy code compares ASHRAE Standard 90.1-2007 with the commercial code in each state as of June 2009. The results are provided in chapters specific to each state.

States with unique energy codes were not included in the analysis because the codes in these states would be difficult to appropriately compare to ASHRAE Standard 90.1 and most of these states have energy offices that routinely assess their codes against the model codes. In states with codes prior to and including the 2000 IECC or Standard 90.1-1999, those states with no statewide energy code, and home rule states which did not specifically request that another code be used, Standard 90.1-1999 was used as the baseline for comparison.

Three DOE Benchmark buildings were used for the simulation used in this analysis: a medium office building (53,600 ft2), a mid-rise apartment building (33,700 ft2), and a non-refrigerated warehouse (49,500 ft2...

This analysis of residential energy code compares the requirements of the 2009 International Energy Conservation Code (IECC) with the residential code—or typical construction practice in the absence of a code—in most states as of June 2009. The results, which include estimated typical energy savings of updating each state’s code to the 2009 IECC, are provided in chapters specific to each state.

Several states have either not adopted a mandatory energy code or developed their own codes which have minimal or no connection to the IECC. The latter—including California, Florida, Oregon, and Washington— were not included in this analysis because the codes in these states would be difficult to appropriately compare to the 2009 IECC and most of these states have energy offices that have already assessed the IECC on their own.

These analyses evaluate the cost-effectiveness of the prescriptive path of the 2015 edition of the International Energy Conservation Code (IECC), relative to the 2006 IECC for all 50 states and the District of Columbia. The analysis covers one- and two-family dwelling units, town-homes, and low-rise multifamily residential buildings covered by the residential provisions of the 2015 IECC. These reports were originally published in October 2015, and updated in February 2016 to update numbers reported in certain results tables.